Simplify the following expression: $y = \dfrac{8q}{5} - \dfrac{q}{10}$
Solution: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $5$ and $10$ $\lcm(5, 10) = 10$ $ y = \dfrac{2}{2} \cdot \dfrac{8q}{5} - \dfrac{1}{1} \cdot \dfrac{q}{10} $ $y = \dfrac{16q}{10} - \dfrac{q}{10}$ $y = \dfrac{16q -q}{10}$ $y = \dfrac{15q}{10}$ Simplify the expression by dividing the numerator and denominator by 5: $y = \dfrac{3q}{2}$